Help needed: backing fabric puckering
 

I'm fairly new to quilting and have run into a problem with my latest project. Every time I quilt the backing it ends up wrinkling. I've tried various solutions -
I've changed the backing fabric
I've pinned with smaller gaps
I've increased stitch length to 3
I've slowed the stitching right down
I'm using a new needle

None of it has worked.

I don't think it's the original sandwich because I've been so careful; securing the fabric to my conservatory floor with tape and then smoothing from the centre out.
But after 6 attempts I'm still getting the problem you can see in the photo

About to unpick yet again and am thinking that it might be easier to do some echo quilting of each block starting from the centre rather than straight lines. (I'm not up to anything more sophisticated than that at the moment)

Thoughts???

Hmm that is a dilemma! I know others will come in and offer good suggestions. My first thought is that maybe when you are taping the backing to the floor you are pulling it too taut? And then when it releases it bounces back?

Are you using a walking foot when quilting? You might want to lengthen the stitch length and if possible reduce the foot pressure.

Thanks Lena, yes I'm using a walking foot. When I started I was using 2.5 stitch length but have now increased that to 3 and it's still an issue. Should I go up to 3.5?
When I look a the stitching closely, I can see that sometimes the stitches are smaller than they should be

I don't have the ability on my machine to change the foot pressure though

I'm not conscious that I'm pulling it but will watch out for that when I try next. I'm having to take the whole thing apart and start again

I used to use safety pins to secure layers for quilting. Some quilt backs ended up like your picture. Then I discovered spray baste spray. Puckers still happened. I was stretching the backside fabric slightly when clipping it onto the table with clips. I figured out that it was "relaxing" too much when released from clips. So, now I'm careful to smooth without pulling, and it worked much better!

Are you alternating the direction of your stitching lines?

Try quilting in only one direction.

if some of your stitches are smaller than others it makes me wonder if the bulk of your quilt is being supported. If the weight of the quilt is dragging it will affect the stitch length. This doesn’t address the puckering on the back. I agree with others who have suggested you may have stretched the backing when you secured it to the floor.

Is your fabric a poly/cotton? How about the type of batting you are using? Is some of the quilt tied before your machine quilting? I have been fortunate with my pin basting, but I also make sure to quilt slow enough to let the walking foot do its’ job to feed the whole sandwich through evenly. It seems we all find what works best for us, have you cleaned the feed dog area on your machine recently? Just some thoughts as I read your post.